1. Field of the Invention
The present invention relates to displacement to electrical manipulation joystick type controllers useful for computer, game console and machinery control for example.
2. Description of the Related Prior Art
Prior art displacement to electrical manipulation joysticks have been manufactured and sold in large numbers over the last several decades. Such prior art joysticks include expensive rotary sensors such as potentiometers or optical encoders, or Hall effect, magnetic sensors or the like for detecting force applied to a handle, and commonly provide for a significant amount of displacement capability of the handle. The terms handle, rod, stick and arm as used in reference to the main riser of joysticks are herein to be generally interchangeable and are intended to apply to the manipulable elongated lever to which an actuating force is applied, such as by a human hand or finger, to affect a control signal.
Many consumers have grown accustomed to the significant handle displacement capabilities and resultant conventional feel and ease of control of such joysticks. Additionally, many users perceive the accuracy of displacement joysticks as being high due to the high displacement capabilities. Many consumers, being accustomed to conventionally feeling displacement joysticks, desire significant displacement capabilities in a joystick, particularly but not limited to when the joystick is used for electronic game control. Consumers are generally unconcerned as to the type of force or movement detecting sensors utilized in a joystick provided the joystick functions well for their purposes. However, consumers are concerned about the purchase price of a joystick, the accuracy and durability thereof, and how the joystick feels during use.
In recent years, prior art joysticks have been developed which utilize variably conductive compression-sensitive material connected in circuitry to affect electricity in the circuit in an analog manner, usually with varying resistance, the resistance varied based on the magnitude of compressive force received by the material. The small size of such compression-sensitive sensors allows such joysticks to be manufactured in a small size, and thus joysticks using such sensors are often designed for cooperative attachment to and use with computer keyboards wherein the arm (lever) extends upward between the adjacent keys of the keyboard to be exposed to force applied by a human finger. In such an arrangement, the keys are quite close to the arm of the joystick and thereby present a situation suitable for use of a joystick having an arm greatly restricted against user detectable displacement of the arm. While such joysticks with very little if any user detectable arm displacement capabilities may be suitable for use mounted in a keyboard with the arm extending upward between keys, such joysticks are unsatisfactory in many other applications, again, because many consumers have grown accustomed to being able to substantially displace the arm of conventional joysticks, and believe such displacement leads to increased accuracy in desired control. Additionally, many believe high displacement of the arm leads to greater enjoyment, particularly when playing certain types of electronic games.
To my knowledge, the compression-sensitive material used as the active component of the compression-sensitive variable-conductance sensors in such joysticks is quite hard, even though it is sometimes called "conductive rubber" due to its typical silicone rubber content. While the material is technically physically compressible in thickness, its ability to reduce in thickness under compression applied by a typical joystick is very limited because the material is fairly hard and generally uncompressible in a joystick.
Examples of typical prior art joysticks which utilize pressure or compression-sensitive sensors for detecting force applied to the arm and which aid in providing analog information related to the direction and magnitude of the applied force are discussed below.
U.S. Pat. 5,659,334 issued Aug. 19, 1997 to S. Yaniger et al, and U.S. Pat. 5,828,363 issued Oct. 27, 1998to S. Yaniger et al each disclose force-sensing pointer devices in the form of joysticks which utilize pressure-sensitive sensors, the joysticks being primarily directed for use in computer keyboards with the arm of the devices extending upward from between the keys. The Yaniger et al arms, being apparently of rigid construction, are rigidly secured at the bottom end to an apparently rigid plate referred to as a force transfer member and which applies force to the sensors. Force against the upper end of the arm of the Yaniger joysticks is transferred through the lower force transfer member and into the sensors. Applied force to the Yaniger arm forces the force transfer member into the sensors, and the sensors are supported against moving away from the force transfer member, thus, when the sensors provide resistance to the force transfer member being displaced, which is generally immediate, resistance against the arm being displaced is also thereby immediately provided since the arm and force transfer member are rigidly and proportionately linked to one another. The arms of the Yaniger et al joysticks are substantially prohibited from any appreciable displacement which the user could feel, and this for numerous structural and use application reasons, but probably the most important applicable reason is the desires of Yaniger et at to intentionally build such joysticks wherein the tip or upper end of the sticks have a maximum travel distance "close or equal to zero." which they believe is ergonomically correct.
European patent application number 94102739.3, publication number 0 616 298 A1 filed Feb. 23, 1994 by inventor Okada Hiroyasu, discloses a joystick type device primarily intended for use in a computer keyboard and which uses pressure sensitive sensors (compression-sensitive variable resistance material) and includes an arm or lever fastened to or resting against a pressing plate, the pressing plate a component for compressing the sensor material such as against a circuit board or the like backing member. With force applied to the Okada Hiroyasu lever, the lever is shown to be inclined by a given angle, and the pressing plate is also shown to be inclined by the same given angle, and thus proportionantly inclined relative to the lever. The Okada Hiroyasu lever has very little displacement capability, and the pressing plate moves proportionantly with the lever.
U.S. Pat. No. 5,689,285 issued Nov. 18, 1997 to D. J. Asher describes a joystick which utilizes a multi-layered membrane sensor. The membrane sensor includes first and second insulating substrates; first and second resistors in the form of closed loops on the respective insulating substrates; a layer of pressure-sensitive resistive material interposed between the resistors, and an actuator including a shaft for transferring force vectors applied to the shaft into the membrane sensor lamination to create signals which after complex computation can be treated as representative of direction and magnitude of the force. The membrane sensor of Asher is relatively expensive, particularly when or if it is interfaced with a conventional style rigid circuit board typically used to support microcontrollers and other electronic components used in joysticks.
Other prior art considered pertinent to this disclosure are described below.
U.S. Pat. No. 5,805,138 issued Sep. 8, 1998, and assigned to IBM Corp. describes a gross motion input controller of very large size and which includes a surface for a user to sit on, and a spring mounted riser member having a plurality of tension-actuated and expensive strain gages mounted inside the riser tube for sensing motion.
U.S. Pat. No. 5,831,596 issued Nov. 3, 1998 to S. Marshall et al discloses a joystick including a resilient control arm for providing a more acceptable feel to a user of the joystick. The Marshall et al joystick does not use pressure or compression sensitive sensors, but instead utilizes relatively expensive Hall effect or magnetic type sensors which detect displacement of the control arm.
U.S. Pat. 4,514,600 issued Apr. 30, 1985 by inventor J. M. Lentz describes a video game hand controller in joystick style which includes a switch assembly including a helical coil spring extending from the area of the switch assembly in a housing into the exposed handle of the unit, the helical spring being bendable with force applied to the stick, the bending causing the spring to make contact with one or more electrical contact pads disposed concentrically around the spring. The spring is electrically conductive and connected to the controller circuitry to serve as one electrical lead of each of the switches. The contact pads produce video game control signals through a normally open, momentary closing of an On/Off switch-like arrangement incapable of producing analog information.
U.S. Pat. 4,349,708 issued Sep. 14, 1982 by inventor J. C. Asher describes a joystick including a deformable resilient annular member superimposed over normally open, momentary-on contact switches so that displacement of the handle of the joystick causes an arcuate portion of the annular member to press against at least one of the switches at a time to cause closing thereof. The switches are activated depending on the direction of displacement of the handle. Displacement of the Asher annular member toward a momentary-On switch appears to be proportionate to the displacement of the handle in the same direction, and the switches and associated circuitry are not analog capable.
U.S. Pat. 5,835,977 issued Nov. 10, 1998 describes a joystick using strain gauge sensors affected by tension, with the post (stick or arm) intentionally structured and supported to have very little displacement capability so as to prevent the excessive stretching and thus damage to the strain gauges. In one embodiment, the post is restrained by an auxiliary post restrainer device in the form of a tube located about the post, with adjustable bolts mounted in the tube and positioned to abut and greatly restrain displacement of the post.
A prior art gimbal using joystick is currently on the market in the U.S. and is made by CH Products of San Marcos, Calif. , USA, and is sold under the trade name of "Flightstick Pro". While the "Flightstick Pro" uses a gimbal; a highly displaceable lever arm connected to rotate two axles; and includes a post member on each axle which abuts arms, the post, arms and tension spring connected across the arms of the "Flightstick Pro" are only for return-to-center of the lever arm. The "Flightstick Pro" utilizes expensive rotary potentiometers as sensors, one per axle, and requires user adjustable centering wheels to be adjusted by the user at the start of play to center the object controlled by the potentiometers. The "Flightstick Pro" does not use compression-sensitive variable-conductance (CSVC) material or CSVC sensors.
Other relevant documents describing prior art joysticks cumulative to the above prior art are: U.S. Pat. Nos. 4,408,103; 5,749,577; 5,767,840; 5,510,812, and German patent DE19519941 published Mar. 13, 1997; and European patent EP0438919 published Jul. 31, 1991.
U.S. Pat. No. 3,806,471 issued Apr. 23, 1974 to R. J. Mitchell is relevant to the structuring and operation of compression-sensitive variable-conductance material and sensors using such material to manipulate electricity in circuitry.